Scientists from Carnegie and Smithsonian museums and the University of Utah have named the sharp-clawed 500-pound bird-like dinosaur ‘Anzu wyliei’.

Anzu means a bird-like demon in Mesopotamian mythology and wyliei is given after a boy named Wylie, the dinosaur-loving grandson of a Carnegie Museums of Pittsburgh trustee.

“It was a giant raptor but with a chicken-like head and presumably feathers. The animal stood about 10 feet tall, so it would be scary as well as absurd to encounter," explained Emma Schachner, a post-doctoral fellow at University of Utah.

“We jokingly call this thing the 'chicken from hell' and I think that is pretty appropriate,” added Matt Lamanna of Carnegie Museum of Natural History in Pittsburgh.

Three partial skeletons of the dinosaur - almost making up a full skeleton - were excavated from the uppermost level of the Hell Creek rock formation in North and South Dakota - a formation known for abundant fossils of Tyrannosaurus rex and Triceratops.

The new dinosaur was 11Â½ feet long, almost 5 feet tall at the hip and weighed an estimated 440 to 660 pounds.

Anzu is the largest oviraptorosaur found in North America.

Oviraptorosaurs are a group of dinosaurs that are closely related to birds and often have strange, cassowary-like crests on their heads.

Anzu with large sharp claws was an omnivore, eating vegetation, small animals and perhaps eggs while living on a wet floodplain.

“Having a nearly complete skeleton of Anzu wyliei sheds light on a category of oviraptorosaur theropod dinosaurs named caenagnathids, which have been known for a century, but only from limited fossil evidence,” Schachner said in a study published in PLOS ONE.